Is there such a thing as a NON-BROODY helping a BROODY?

First of all, I LOVE my little broodies! But I have a question, my Black Cochin Bantam is broody and another Gray Cochin Bantam is setting right along with the black one and defending the eggs, whether there are really eggs or not!

She puffs up just like the black one and pecks when you reach under her but she is still laying. If it were not for her laying, I would be convinced that she is broody also, judging by her behavior. I know for a fact that she is laying as the only other girls I have with the two little Cochins are 4 RIR pullets and their eggs are much larger and completely different in color.

BTW, both of the little Cochins are mixes (as far as I know) but they do look like Cochins, especially the black one. The black one could be purebred, but that would have happened completely by accident, as we hatched these two from eggs given to us by someone who allows all of his chickens and roosters to mingle.

i have things like this happen... i usually just take the one with NO eggs and kick her out of the box... and MARK the eggs that the broody is sitting on ..
some very broody hens will try to take over a nest for another...
or some hens will want to keep laying their eggs in the same box, and just shove the sitter over a bit so she can deposite her egg in the nest.. if you mark the eggs, you will know if another hen has slipped in an additional egg.
last year i had a bantie hen steal 2 eggs from another bantie hen.. they sat right next to each other, kept switching eggs and nests..i did not think it was going to work but all the eggs hatched (4 chicks) and BOTH hen took care of the chicks.. it was the strangest thing

thats cool ... but , thats why I remove my broody hen with HER NEST and eggs and put her in a private cage or area where she will not be disturbed . She is alot more calm that way . Just make sure she has plenty of fresh food and water close by . 21 days later and you will be very EGGCITED

Less problems that way . She will attend to her nest and roll the eggs herself .